S&S CYCLE Cams - HP103 - Chain Drive 330-0343

If you're running a Big Twin and tired of timing chain slop killing your valve timing accuracy, the S&S Cycle HP103 gear drive kit eliminates that problem entirely. By replacing chain drive with precision gears, you gain tighter valve control, unlock higher cam lift potential, and access a broader power band—especially valuable if you're building a lighter bike that needs to breathe hard in the mid-to-high RPM range. This is a serious upgrade for riders who demand reliability and performance over stock compromises.

Installation requires professional-level fabrication: you'll need a hydraulic press, material removal from the stock gear cover, and expertise to verify clearances. Plan accordingly and budget for a qualified technician if you're not equipped for this level of work.

• Gear drive eliminates chain lash
• Increases valve timing accuracy
• Enables higher cam lifts
• Reversed rear cam rotation
• Additional lobe operating clearance
• Fits 103" and 106" Big Bore
• Compatible with stock heads
• Up to 10.2 compression ratio
• Peak power 3500–6000 rpm
• Requires high-performance valve springs (99–04 models)
• Includes cams and bearings
• Inner and outer gears included
• Gasket and instructions included
• Cam bearings must be replaced
• Requires coil bind verification
• Requires valve-to-valve clearance check
• Requires valve-to-piston clearance check
• May increase valve train noise
• Made in U.S.A.
• Professional installation recommended